Fernández‐Fernández 2010.

Methods	A patient series of cardiac adverse effects of methylphenidate treatment
Participants	Diagnosis of ADHD: DSM‐IV‐R (subtype: combined) Age: 7, 8, and 10 years old IQ: > 85 Sex: 3 males Ethnicity: not stated Country: Spain Comorbidity: no cardiovascular diseases Comedication: not stated Sociodemographics: not stated
Interventions	Case 1 Extended release osmotic release oral system methylphenidate, 36 mg/day for 18 months. Treatment compliance: not stated Extended release osmotic release oral system methylphenidate, 18 mg/day. Treatment compliance: not stated Case 2 Extended release osmotic release oral system methylphenidate, 18 mg/day, > 9 months. Treatment compliance: not stated Case 3 Extended release osmotic release oral system methylphenidate, 18 mg/day. Treatment period: not stated. Treatment compliance: not stated Discontinuation Re‐administration of extended release osmotic release oral system methylphenidate, 18 mg/day. Treatment period: not stated. Treatment compliance: not stated
Outcomes	Serious adverse events: Case 3 Re‐administration of extended release osmotic release oral system methylphenidate, 18 mg/day: recurrence of episodes of tachycardia. Emergency department: supraventricular tachycardia treated with adenosine Non‐serious adverse events: Case 1 Extended release osmotic release oral system methylphenidate, 36 mg/day, 12‐18 months: elevated arterial blood pressure with 2 SDs. No other intercurrent factors or symptoms Extended release osmotic release oral system methylphenidate, 18 mg/day: normalisation of blood pressure Case 2 Extended release osmotic release oral system methylphenidate, 18 mg/day, 6 months: repetitive episodes of self‐limiting tachycardia. Duration: a few minutes. ECG: self‐limiting sinus tachycardia, 150 beats/minute. Maintaining methylphenidate treatment for > 3 months: some episodes of tachycardia Case 3 Extended release osmotic release oral system methylphenidate, 18 mg/day: several episodes of tachycardia
Notes	Funding/vested interests: not stated Authors' affiliations: Unidad de Neurologiá Pediátrica. Hospital Universitario Infantil Virgen del Rocío. Sevilla, España Key conclusions of the study authors: these cases should make us be cautious and investigate the possible existence of family or personal cardiovascular pathology Comments from the study authors: to date, our patient is the youngest one diagnosed with supraventricular tachycardia secondary to methylphenidate treatment Supplemental information regarding ADHD diagnostic criteria and IQ received through personal email correspondence with the authors in August 2013 (Fernández‐Fernández 2013 [pers comm])